<template>
    <el-breadcrumb class="app-breadcrumb" separator="/">
        <transition-group name="tl-breadcrumb">
            <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path + index">
                <span v-if="item.redirect === 'noRedirect' || index === levelList.length - 1" class="no-redirect">{{ item.meta.title }}</span>
                <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
            </el-breadcrumb-item>
        </transition-group>
    </el-breadcrumb>
</template>

<script>
import * as pathToRegexp from 'path-to-regexp';

export default {
    name: 'index',
    components: {},
    data: function () {
        return {
            levelList: null
        }
    },
    methods: {
        getBreadcrumb () {
            // 仅显示带有meta.title的route
            let matched = this.$route.matched.filter(item => item.meta && item.meta.title)
            const first = matched[0]

            if (!this.isDashboard(first)) {
                matched = [{ path: '/admin/dashboard', meta: { title: '控制台' } }].concat(matched)
            }

            this.levelList = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
        },
        isDashboard (route) {
            const name = route && route.name
            if (!name) {
                return false
            }
            return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
        },
        pathCompile (path) {
            const { params } = this.$route
            const toPath = pathToRegexp.compile(path)
            return toPath(params)
        },
        handleLink (item) {
            // const { redirect, path } = item
            // if (redirect) {
            //     this.$router.push(redirect)
            //     return
            // }
            // this.$router.push(path)
            const { redirect, path } = item
            if (redirect) {
                console.log(redirect, path)
                this.$router.push(redirect)
                return
            }
            this.$router.push(this.pathCompile(path))
        }
    },
    watch: {
        $route (route) {
            // if you go to the redirect page, do not update the breadcrumbs
            if (route.path.startsWith('/redirect/')) {
                return
            }
            this.getBreadcrumb()
        }
    },
    created: function () {
        this.getBreadcrumb();
    }
}
</script>

<style lang='less' scoped>
.app-breadcrumb.el-breadcrumb {
    display: inline-block;
    font-size: 14px;
    line-height: 50px;
    margin-left: 8px;

    .no-redirect {
        color: #97a8be;
        cursor: default;
    }
}
</style>
